Lawrence Livermore National Laboratory (LLNL) - a US government (Department of Defense, Department of Energy) scientific and engineering laboratory in Livermore, CA. operated by the University of California. It was founded in the 1950s by Ernest Lawrence and Edward Teller to counteract the Russian hydrogen bomb threat. Its sister lab is Sandia National Labs.

Bill Clinton signed the Comprehensive Test Ban Treaty in 1996, banning underground nuclear testing. Thus now the lab's nuclear responsibility is the science-based "Stockpile Stewardship", i.e. making sure the remaining nuclear weapons work perfectly without the ability to test them or create new ones. This now involves using extensive computer simulation, the Accelerated Strategic Computing Initiative (ASCI); the IBM RS/6000 "ASCI White" is the world's fastest supercomputer.

A facility currently under construction, almost complete is the National Ignition Facility (NIF), for the Inertial Confinement Fusion program. It will use the world's largest laser to test fusion experiments. For its extensive laser programs LLNL has often been backronym-described as "lasers, lasers, nothing but lasers."

Actually the lab is vastly diverse and also has programs in fields such as biology and chemistry.